Add default SecureStore implementation

Provides default SecureStore implementation that behave same as current
internal Gerrit implementation

Change-Id: Iafcc01a4a0d57b5e54e61dc8b9d270bb213fa44f
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>

gerrit-server/src/main/java/com/google/gerrit/server/securestore/DefaultSecureStore.java

@@ -0,0 +1,98 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.securestore;
+
+import com.google.gerrit.common.FileUtil;
+import com.google.gerrit.extensions.annotations.Export;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import org.eclipse.jgit.internal.storage.file.LockFile;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
+import org.eclipse.jgit.util.FS;
+
+import java.io.File;
+import java.io.IOException;
+
+@Singleton
+@Export(DefaultSecureStore.NAME)
+public class DefaultSecureStore implements SecureStore {
+  public static final String NAME = "default";
+
+  private final FileBasedConfig sec;
+
+  @Inject
+  DefaultSecureStore(SitePaths site) {
+    File secureConfig = new File(site.etc_dir, "secure.config");
+    sec = new FileBasedConfig(secureConfig, FS.DETECTED);
+    try {
+      sec.load();
+    } catch (Exception e) {
+      throw new RuntimeException("Cannot load secure.config", e);
+    }
+  }
+
+  @Override
+  public String get(String section, String subsection, String name) {
+    return sec.getString(section, subsection, name);
+  }
+
+  @Override
+  public void set(String section, String subsection, String name, String value) {
+    if (value != null) {
+      sec.setString(section, subsection, name, value);
+    } else {
+      sec.unset(section, subsection, name);
+    }
+    save();
+  }
+
+  @Override
+  public void unset(String section, String subsection, String name) {
+    sec.unset(section, subsection, name);
+    save();
+  }
+
+  private void save() {
+    try {
+      saveSecure(sec);
+    } catch (IOException e) {
+      throw new RuntimeException("Cannot save secure.config", e);
+    }
+  }
+
+  private static void saveSecure(final FileBasedConfig sec) throws IOException {
+    if (FileUtil.modified(sec)) {
+      final byte[] out = Constants.encode(sec.toText());
+      final File path = sec.getFile();
+      final LockFile lf = new LockFile(path, FS.DETECTED);
+      if (!lf.lock()) {
+        throw new IOException("Cannot lock " + path);
+      }
+      try {
+        FileUtil.chmod(0600, new File(path.getParentFile(), path.getName()
+            + ".lock"));
+        lf.write(out);
+        if (!lf.commit()) {
+          throw new IOException("Cannot commit write to " + path);
+        }
+      } finally {
+        lf.unlock();
+      }
+    }
+  }
+}